"Our analyses reveal the Mediterranean Sea as one of the world's most dangerous places on Earth for sharks and rays," Claudine Gibson, IUCN Shark Specialist Group program officer and co-author of the report, said in a statement.

"Bottom-dwelling species appear to be at greatest risk in this region, due mainly to intense fishing of the seabed."

A total of 71 species were assessed. Of the 30 species deemed threatened with extinction, 13 were classified as critically endangered, 8 as endangered, and 9 as vulnerable.

Only ten species (14 percent) were considered free of any extinction risk.

Almost Gone

Critically endangered species include the seabed-hugging Maltese skate (Leucoraja melitensis), which lives only in the Mediterranean. Bottom-trawl fishing is the main cause of recent population declines of 80 percent, the IUCN report says.

The shortfin mako shark (Isurus oxyrinchus) and porbeagle shark (Lamna nasus), both prized for their meat and fins, were likewise found to be critically endangered.

"We are particularly concerned about the porbeagle and mako sharks," said shark expert Alen Soldo of the University of Split, Croatia, who participated in the study. "Our studies reveal persistent fishing pressure well in excess of the reproductive capacity of the species."